Transparent coatings find numerous applications in modern devices. For example, transparent coatings can be used for coating windshields, air craft windows, cell phone screens, tablet screens, computer screens, weapon heads, field deployed sensors, lasers, light emitting diodes (LEDs), etc. These coatings need to be transparent, scratch resistant, have high hardness, corrosion resistance, and generally provide protection from the environment.
State of the art transparent coatings are often deposited at high temperatures, for example, a temperature of greater than about 500 degrees Celsius. Such state of the art coatings are often formed from oxides (e.g., titanium oxide, indium tin oxide, aluminum doped zinc oxide, zinc doped indium oxide, etc.) which do not possess high wear resistance and can degrade in corrosive environments.
Furthermore, there is also an increasing demand for transparent semi-conductor devices. For example, traditional solar cells are fabricated on silicon which is opaque. Only one surface of such solar cells is available for receiving light and generating electricity therefrom. There is also a demand for other semi-conductor devices such as p-n junction devices, LEDs, other diodes, transistors, etc.
Moreover, high power high temperature semi-conductor devices produce a substantial amount of heat which needs to be dissipated for proper operation of the semi-conductor devices. Coatings can be used to provide heat dissipation. Conventional coatings for thermal management or otherwise dissipation of heat produced by such semi-conductor devices are generally disposed at high temperatures (e.g., greater than 800 degrees Celsius). At such high temperatures, the semi-conductor materials used to fabricate the semi-conductor devices (e.g., gallium nitride (GaN), gallium arsenide (GaAs), indium gallium nitride (InGaN), aluminum GaN (AlGaN), etc.) become unstable and can degrade. Furthermore, for some semi-conductor devices such as LEDS, the thermal management coatings should be transparent to allow flow of photons through the coating.